Participant baseline characteristics
| Variable | ILF-NF + TAU* n = 46 | TAU only* n = 47 |
|---|---|---|
| Age, yr | 39.6 ± 12.6 | 36 ± 11.8 |
| Male | 30 (65) | 31 (66) |
| Education level | ||
| Primary school or less | 18 (39) | 24 (51) |
| High school | 21 (46) | 16 (34) |
| Bachelor’s degree or higher | 5 (11) | 5 (11) |
| Living alone | 22 (48) | 24 (51) |
| Problematic substance use, yr† | 9.2 ± 8.2 | 9.9 ± 8.7 |
| Working days in the past 30 d | 3.5 ± 6.8 | 3.7 ± 9.2 |
| EuropASI score‡ | ||
| Alcohol use | 0.15 ± 0.19 | 0.14 ± 0.19 |
| Drug use | 0.04 ± 0.1 | 0.04 ± 0.1 |
| Mental distress§ | 2.39 ± 0.52 | 2.47 ± 0.67 |
| Sleep quality¶ | 4.1 ± 2.3 | 3.9 ± 3.0 |
| Restlessness¶ | 5.5 ± 2.2 | 6.4 ± 1.8 |
| Obsessive thinking¶ | 6.6 ± 2.3 | 6.7 ± 2.8 |
| Perceived functioning** | 20.0 ± 8.4 | 19.2 ± 8.8 |
| QoL-5 score†† | 0.51 ± 0.13 | 0.50 ± 0.16 |
EuropASI = Addiction Severity Index, European version; ILF-NF = infralow frequency neurofeedback; TAU = treatment as usual.
↵* Data are presented as n (%) or mean ± standard deviation.
↵† Problematic use of major drug(s) of abuse, as defined in EuropASI, was the consumption of 5 or more standard drinks at least 3 times weekly, or binge drinking on 2 consecutive days to a level that afflicted daily functioning.
↵‡ Measures substance use severity using a composite score of 0 (no problem) to 1 (severe problem).
↵§ Measured using the Hopkins Symptom Check List 10 (SCL-10). Responses are scored on a 4-point scale of 1 to 4 and averaged to a global severity index; a higher score indicates higher distress.
↵¶ Measured using 10 cm visual analogue scales. The sleep quality scale ranged from “poor” to “good,” and the restlessness and obsessive thinking scales ranged from “none” to “very high.”
↵** Measured using the Outcome Rating Scale; scores range from 0 to 40, and higher scores indicate better functioning.
↵†† Measured using the QoL-5 scale, ranging from 0.1 to 0.9, where 0.9 is the highest or best score.